Devices for injection and dosing

ABSTRACT

Injection devices are provided which include a handpiece capable of housing a cartridge containing an injectable composition, and a head coupled to the handpiece and housing a plurality of retractable needles and a dosing mechanism. Methods of treating skin surfaces are also provided.

This application claims the benefit of U.S. Patent Application Ser. No.62/058,587 filed on Oct. 1, 2014, and claims the benefit of U.S. PatentApplication Ser. No. 62/187,077, filed on Jun. 30, 2015, the entirecontents of each of these applications being incorporated herein by thisspecific reference.

The present invention generally relates to mechanisms for injection anddosing, and more specifically relates to devices for providing minutedoses of dermal filler composition superficially into skin.

BACKGROUND

Aesthetic dermal filler procedures have become increasing popular inrecent years, as they have proven to be quite effective in improving theappearance of the face, for example, in reducing the signs of aging bysmoothing wrinkles and folds, such as the nasolabial folds, and plumpingthe midface. Some of the more popular dermal fillers are soft, colorlessgel compositions made of hyaluronic acid. Hyaluronic acid (HA) is a longchain polymer, more specifically, a polysaccharide, which occursnaturally in body tissues. When chemically crosslinked, hyaluronic acidmakes an excellent, long lasting, dermal filler material. Dermal fillerprocedures are quite minimally invasive, and the results are nearlyimmediate. Further, hyaluronic acid naturally degrades in the bodytissues, and thus the fillers are temporary, for example, lastingseveral months to a year or more. Further, results of hyaluronic acidbased dermal filler procedures can be reversed using hyaluronidase.

Conventional dermal filler procedures are generally performed byinjection of the composition into or below the skin using a standardsyringe and a fine gauge needle. A typical dermal filler patient mayundergo from about 5 to about 10 injections in a single procedure, withinjection points across various regions of the face. While the goal maybe to improve the appearance of the entire face, a skilled aestheticphysician generally aims to correct one or more specific regions of theface, for example, regions that lack volume such as the lips or thecheeks, or regions that present specific wrinkles, such as deepnasolabial folds, with specific input from the patient regarding areashe or she finds detracting to his or her appearance.

It has been discovered that improvement of facial appearance can also beaccomplished by introducing minute amounts of compositions into skin ata very superficial depth, and across wide regions of the skin, ratherthan focusing on specific wrinkles or specific areas of the face thatlack volume.

SUMMARY

The present invention is generally directed to a device that can be usedto deliver a composition into skin, for example, in a way that iseffective to treat or improve the skin surface. The device is structuredfor treating or improving skin by delivering a composition, for examplea gel, for example, a dermal filler gel, into skin, at a relativelyshallow depth, to improve the appearance of the skin, and perhapsimprove overall skin health and quality. The device advantageouslyfacilitates treatment of a large surface area of skin, such as theentire face, neck and/or décolletage, or significant regions thereof.The device allows for controlled depth of injection, especially forsuperficial intradermal delivery of compositions, for example, dermalfiller gels or other compositions effective to enhance the health orappearance of skin. The injection may be between about 0.5 mm about 3 mmfor intradermal injection, or deeper for subdermal injection.

For example, the device is more efficient at delivering doses of ahyaluronic acid based dermal filler to a large surface area of skin thanis currently possible with a standard needle and syringe.

In some embodiments, a dermal filler injection device is provided whichgenerally comprises a handpiece including a housing having an interiorspace for containing a cartridge and a trigger coupled to the housing.The device further includes a head in communication with the interiorspace. In some embodiments, the head is removable with respect to thehandpiece. In some embodiments, the device includes at least oneretractable needle and at least one dosing chamber coupled thereto.Operation of the trigger causes the needle to be moved from a retractedposition to an extended position and a dose of a composition to bedelivered from the needle tip.

In some embodiments, the at least one needle comprises a plurality ofneedles, with each one of the needles coupled to a corresponding one ofthe dosing chambers. In this embodiment, the device may be structuredsuch that operation of the trigger initially causes the plurality ofneedles to be moved from a retracted position to an extended positionand subsequently causes a dose of fluid contained in the correspondingdosing chambers to be ejected from the needles, for example,substantially simultaneously, when the needles are in the extendedposition. The device may be further structured to cause retraction ofthe needles after the dosing. In some embodiments the device includes amechanism capable of filling each dosing chamber between subsequentinjections.

The plurality of needles may comprise linearly arranged needles, forexample, at least three, for example, about four, or more linearlyarranged needles. In some embodiments, the needles are arranged in anarray. For example, the needles may be arranged in a two by two array, atwo by three array, a four by four array, a six by six array, a two byfour array, or any other suitable configuration.

In one embodiment, the head of the device may include a plurality ofconical or tapered projections, each needle having a tip protruding froman individual conical or tapered projection. For example, each conicalor tapered projection is spaced apart from each other conical or taperedprojections so as to effect a preloading of skin when the head isapplied to skin, to facilitate penetration of the needle tips into theskin.

In one aspect, a method for treating skin is provided, wherein themethod generally comprises placing a distal end of a handheld deviceinto direct contact with skin to be treated; causing the device toinject a dose of a composition into the skin through a plurality ofneedles, substantially simultaneously; moving the distal end of thedevice onto another portion of the skin while maintaining the directcontact with the skin; and, after the step of moving, causing the deviceto inject another dose of the composition into another portion of theskin. In another aspect of the invention, the needles are in a retractedposition during the moving step. The needles are in an extended positionduring the dosing or delivery of the composition into the skin.

BRIEF DESCRIPTION OF THE DRAWINGS

The various aspects and advantages of the different embodiments may bebetter understood by referring to the following Detailed Description andaccompanying Drawings of which:

FIG. 1 shows a perspective view of a device in accordance with anembodiment of the invention;

FIG. 2 shows a cross-sectional view of the device shown in FIG. 1, thedevice in a neutral position;

FIG. 3 shows a cross-sectional view of the device shown in FIG. 1, thedevice in an initial stage of trigger activation;

FIG. 4 shows a cross-sectional view of the device shown in FIG. 1, thedevice in a stage of full trigger activation;

FIG. 5 shows a cross-sectional view of the device shown in FIG. 1, thedevice in an initial stage of trigger retraction;

FIG. 5A shows an alternative one-way mechanism useful in someembodiments of the invention;

FIG. 6 shows a cross-sectional view of the device shown in FIG. 1, thedevice in a neutral position;

FIG. 7 shows a magnified view of a distal end of the device taken fromFIG. 2.

FIG. 8 shows a magnified view of the distal end of the device taken fromFIG. 3.

FIG. 9 shows a magnified view of the distal end of the device taken fromFIG. 4.

FIG. 10 shows a magnified view of the distal end of the device takenfrom FIG. 5.

FIG. 11 shows a magnified view of the distal end of the device takenfrom FIG. 6.

FIG. 12 shows a cutaway view of the distal end of the device duringinjection.

FIGS. 13-15 show perspective views of the device including a removablehead feature.

FIG. 16 shows the device of FIG. 1 with a removable cartridge.

FIG. 17 shows an alternative embodiment of the device of the invention.

DETAILED DESCRIPTION

A device 10 in accordance with an exemplary embodiment of the inventionis shown in FIG. 1. Device 10 is configured and shaped to be held andoperated by a single hand of a user, for example an aesthetic physician.Device may be used to deliver micro-depot injections of composition intoskin, with the aim of improving the appearance of skin, for example,reducing the appearance of fine lines or superficial skin depressions,thereby improving skin texture. Depending on the composition beingdelivered, device 10 may also be effective for use in improving orincreasing skin elasticity and hydration.

Device 10 generally comprises a handpiece 12, and a head 14 coupledthereto. The handpiece 12 includes a main housing 18, and a trigger 16coupled to the main housing 18.

As shown in FIGS. 2-4, device 10 is shown in the several operationalstages that occur during operation of the device 10 when used to delivermultiple, shallow, doses of a composition 19 into skin.

Turning now to FIG. 2, the device 10 is shown, in cross-sectional view,in a neutral position, for example, a position of which the device 10 isnot yet actuated, and is ready to be used to introduce the composition19, for example, a dermal filler, for example, a crosslinked and/oruncrosslinked hyaluronic acid-based dermal filler, or other beneficialcomposition.

When the device 10 is in the neutral position, needles 22 of the device10 are positioned in a retracted position within the head 14. At thisstage, handpiece 12 is comfortably grasped by the user, and is placedinto contact with a region of a patient's skin (not shown) to betreated, with the head 14 of the device 10 touching the skin.

FIG. 3 shows the device 10 during an initial stage of the trigger 16being manually pressed, for example by a thumb or index finger of theuser, in which the needles 22 are caused to be moved to an extendedposition. As the needles 22 extend, they are caused to puncture thesurface of the skin in contact with the head 14.

Turning to FIG. 4, as the user continues to press trigger 16, multiplesmall, shallow doses 2, aliquots, or micro depots of the composition,are delivered from the extended needles 22 and into the skin.

Needles may be spaced apart from one another any suitable distance. Inthe embodiment shown, adjacent needles are spaced apart about 10 mm. Inother embodiments, the spacing between adjacent needles may be, forexample, less than 10 mm, for example, about 3 mm, about 5 mm, about 7mm. In yet other embodiments, the needles are spaced apart more than 10mm, for example, about 12 mm, about 14 mm, about 16 mm, or about 20 mm,or more. In yet other embodiments, spacing between adjacent needles isabout 1 mm to about 20 mm, for example, about 3 mm to about 14 mm, forexample, about 5 mm to about 12 mm, for example, about 7 mm to about 10mm.

As illustrated in FIG. 5, as the user initially releases pressure on thetrigger 16, the needles 22 remain for a moment in the extended position,while the dosing of composition from the device 10 is stopped. FIG. 6shows that upon completion of the release of the trigger 16, the needles22 have moved back into the retracted position, and the device 10 onceagain in the neutral position, is ready to be actuated for the nextdose.

The operational mechanism of device 10 may be more clearly understoodwith reference to the magnified views of FIGS. 7-11.

Turning now to FIG. 7, head 14 comprises a needle array housing assembly32, and a needle hub 34 disposed within the needle array housingassembly 32. A plurality of needles 22, for example, four needles 22,are secured in the needle hub 34. A needle assembly spring 38 is seatedbetween the needle array housing assembly 32 and the needle hub 34.

Needles 22 may be arranged linearly, as shown, for example, arranged ina single row of three or more, for example, four to about 20 or more,needles. The exemplary embodiment shown comprises a 1×4 needle array.Alternative devices of the invention including different needle arrayarrangements include other devices having other arrays, such as, forexample but certainly not limited to, a 1×3 array, a 3×3 array, a 2×3array, or a 4×4 needle array 212, such as device 210 shown in FIG. 17.Any other suitable needle array (e.g. a×b, wherein a is at least one andup to 20, or more, and b is at least one and up to 20, or more), may beprovided within the scope of the invention.

Needle array housing assembly 32 comprises a needle portion 42 havingdistal projecting regions 44, for example, four projecting regions 44,each distal projecting region 44 having an aperture 46 for receiving oneof the needles 22, and a recess 47. Needle array housing assembly 32further comprises a contact portion 48 having a distal surface 52generally circumscribing the distal projecting regions 44. Needle arrayhousing assembly 32 further comprises a base portion 54, which may abutagainst main housing 18 of handpiece 12.

In some embodiments, the device 10 is structured to facilitateinjection. For example, the projecting regions 44 are in the form ofconical or tapered projections, as shown, with each needle 22 protrudingfrom an individual conical or tapered projection 44. In someembodiments, each conical or tapered projection 44 is spaced apart fromeach other conical or tapered projections so as to effect a preloadingof skin when the head 14 is applied to skin during treatment. Bypreloading of the skin, the conical or tapered portions 44 facilitatepenetration of the needle tips into the skin.

Needle hub 34 comprises a first portion 56 and a second portion 58rigidly secured together and holding the needles 22. First portion 56includes hub projecting regions 59, for example, four hub projectingregions 59. Each hub projecting region 59 is aligned with a recess 47 ofa corresponding distal projecting region 44 of the needle array housingassembly 32, as shown.

Briefly turning back to FIG. 2, the handpiece 12 includes an internalassembly 70, which, upon manual activation of trigger 16, is urgedforward, i.e. distally, within the handpiece main housing 18, to causedispensing of an accurate, shallow dose of the composition 19 into skinby way of the needles 22, as will be described in greater detailhereinafter.

Referring back to FIG. 7, internal assembly 70 generally comprises adistribution manifold 72, a dosing manifold 74, a dosing block 76, adosing spring 77, and a one-way mechanism 78 (see briefly FIG. 5 or FIG.16). Distribution manifold 72 and dosing manifold 74 are rigidlyconnected together and sealed. Referring briefly to FIG. 12, dosingmanifold 74 includes individual plungers 79 which correlate withindividual dosing chambers 80 in the dosing block 76. Although they arenot all visible in the Drawings, in this exemplary embodiment, there arefour dosing chambers 80 and four corresponding dosing plungers 79, sincethe shown embodiment includes four needles 22.

Although the exemplary device 10 is a four needle embodiment, it shouldreadily be appreciated that other embodiments of the device not shownmay include any number of needles, for example, less than four, forexample, two or three, or more than four, for example, five, ten, twentyor more, wherein the device is structured such that each needle has acorresponding dosing chamber and individual plunger, with the requiredmodifications to the components of the invention, and all theseembodiments are considered to fall within the scope of the invention.

As shown most clearly perhaps in FIG. 2, the handpiece 12 includes aninterior space, for example, defined by the handpiece main housing 18,for receiving a cartridge assembly 82. The device 10 is structured suchthat the cartridge assembly 82 is removable from the handpiece mainhousing 18 and replaceable. Cartridge assembly 82 comprises a cartridge84 containing the composition 19 to be injected, and a cartridge plunger86 slidable within the cartridge 84 and including plunger head 88 incontact with composition 19. Cartridge 82 includes cartridge distalportion 92.

As shown in FIG. 5, the one-way mechanism 78 may be in the form of anymechanical structure that allows cartridge plunger 86 to move only inthe distal direction during operation of the device 10. For example,one-way mechanism 78 may be in the form of elements 78 a, such asleaves, for example, rigid or flexible leaves, that taper inwardlyagainst and/or otherwise engage the cartridge plunger 86 and prevent thelinear motion of that cartridge plunger 86 in one of two directions, forexample, prevent the movement of the plunger 86 in a reverse or proximaldirection, while enabling the plunger 86 to move in a forward, or distaldirection. Alternative mechanisms are also contemplated and consideredto be within the scope of the invention. For example, the one-waymechanism may be in the form of gears 78 b and teeth 78 c on plunger,such as shown in simplified view in FIG. 5A, such that the cartridgeplunger 86 can move forwardly, but not backward.

Referring back to FIG. 7, distribution manifold 72 includes flangestructure 94 which is mateable with cartridge distal portion 92. Forward(distal) motion of the cartridge plunger 86 pushes composition containedin the cartridge 84 forward and toward distribution manifold where it isdistributed among the dosing chambers 80, and eventually ejected fromthe needles 22.

The dosing chambers 80 may each be sized to contain a drop or an aliquotof composition to be injected. By way of example only, the dosingchamber 80 may be sized or structured to contain at least 2 μl and up toabout 100 μl or 200 μl or greater of a composition. For example, in someembodiments, the dosing chamber 80 is sized and/or structured to containbetween about 2 μl and about 100 μl of a composition, for example,between about 5 μl and about 50 μl, for example, between about 10 μl andabout 40 μl of composition per dosing chamber 80. In some embodiments,each dosing chamber 80 is sized and/or structured to contain, forexample, about 20 μl, about 40 μl, about 60 μl, about 80 μl, about 100μl, or more of a composition.

Briefly referring to FIG. 16, cartridge assembly 82 may be removablefrom the handpiece 12, and replaceable. As shown, main housing 18includes pivotable portion 98. Pivotable portion 98 may encompass thetrigger 16. To replace the cartridge assembly 82, cartridge distalportion 92 snaps into flange structure 94 of distribution manifold 72,as well as retaining clips 95 of the distribution manifold 72, andcartridge plunger 86 is coupled to one-way mechanism 78. Once thecartridge assembly 82 is loaded into the handpiece 12, pivotable portion98 is pivoted closed and the device 10 is in the neutral position (FIGS.2 and 7) and is ready to use. In alternative embodiments, the cartridgeassembly is refillable, but not readily removable by a user of thedevice.

Turning to FIG. 8, the user begins to press the trigger 16 in thedirection indicated by arrow 99.

As the trigger 16 moves, a cam surface 96 on an internal portion of thetrigger 16 presses on rollers 106 (see FIG. 12) which are attached tothe distribution manifold 72. This action moves the distributionmanifold 72, dosing manifold 74, dosing block 76, and one-way mechanism(not shown in FIG. 8), cartridge 84, cartridge plunger (not shown inFIG. 8), and needle hub 34 forward, compressing needle assembly spring38. This causes the needles 22 to be extended relative to portion 42 ofneedle array housing assembly 32, and past the distal surface 52. In theshown embodiment, the needles extend approximately 0.5 mm to about 2.0mm, or more specifically, about 1.5 mm. It can be appreciated that theneedles may extend a distance less than 0.5 mm or greater than 2.0 mm,in accordance with different embodiments of the invention.

Once the needle hub 34 has fully compressed the needle assembly spring38, and has reached the limit of its travel, the needle hub 34 anddosing block 76 and one way mechanism stop moving, and the dosing spring77 begins to compress. As shown in FIG. 9, as the dosing spring 77compresses, the distribution manifold 72, dosing manifold 74, cartridge84 and cartridge plunger (not visible in FIG. 9) continue to moveforward (distally).

Turning briefly back to FIG. 12, the individual plungers 79 of thedosing manifold 74 deliver small doses 2 of the composition 19 throughthe needles 22 by compressing the dosing chambers 80 defined in thedosing block 76, which is not moving with respect to the housing 18.(Prior to this stage, the dosing block 76 was slidable with respect tothe housing 18). Check valves 108, closed during dosing, may be providedto prevent composition 19 from flowing back into the cartridge 84. Whenthe trigger 16 is fully compressed (FIGS. 4, 9 and 12), the dose isfully delivered.

The present invention may further include a mechanism capable of fillingeach dosing chamber between subsequent injections. For example, turningto FIGS. 5 and 10, when the trigger 16 is released, the dosing spring 77is the first to expand, which pushes the distribution manifold 72/dosingmanifold 74 and cartridge 84 back (proximally), but the cartridgeplunger 86 gets trapped in one-way mechanism 78 and cannot move backwith the cartridge 84. The cartridge 84 moving back over the stationarycartridge plunger 86 causes liquid to flow from the cartridge 84 throughthe distribution manifold 72/dosing manifold 74 going through the checkvalves 108 (not visible in FIG. 10). In some embodiments, the needlediameter is small relative to other flow paths and acts as a shut offvalve during the filling of the dosing chambers. so the injectablecomposition does not leak out the needles. Once full, the dosing spring77 can no longer expand the assembly and now the whole internal assemblystarts to move back under the force of the needle assembly spring 38.This retracts the needles 22 back into the device 10 (see FIG. 11) andit is now ready for another cycle.

Advantageously, in some embodiments, head 14, or at least the needleportion thereof, is detachable and replaceable from the handpiece 12.This feature is shown in FIGS. 13-14. In use, head 14 may be replaced atthe same time cartridge (not shown in FIGS. 14-16) is replaced, forexample, after a certain number of injections, thus providing new, sharpneedles for each subsequent use. For example, head 14 is detachable fromhandpiece 12, and can be replaced with another head, for example, anidentical head, by rotating head 14 with respect to handpiece 12. Thismay be accomplished in a number of ways, for example, the device 10 maybe structured such that replacing head 14 comprises the steps ofmanually placing head 14 onto handpiece 12 at 90° out of alignmenttherewith, and subsequently twisting or rotating head 14 clockwise 90°into alignment to lock it in place on handpiece 12. Removing head 14 maybe accomplished, for example, by performing the steps in reverse.

In the shown embodiment, head 14 is separable from a distal hub 112portion of handpiece 12 which houses dosing block, dosing spring, anddosing manifold. Thus, in this particular example, head 14, includingthe needle array housing assembly 32, needles 22, needle hub and needleassembly spring, as described and shown elsewhere herein, is replaceablewith respect to the handpiece 12. In alternative embodiments,replaceable components may include one or more components or portions ofthe dosing manifold or distribution manifold. Needles 22 may be in aretracted position when the head 14 is separated from handpiece 12.Distal hub 112 may include coupling threads 114 or other suitablestructure, for engaging mating threads or other structure (not shown)within head 14.

Methods of using device 10 for treatment or improvement of skin are alsoprovided. For example, a method comprises providing a device such asdescribed and shown herein.

A user, for example, a physician or an aesthetician, selects a region ofskin to be treated on a patient. Potential skin regions that may benefitby treatment with device include the entire face, or portions thereof,including the forehead, the cheek, the nose, and the chin, the neck, thedécolletage, the shoulders, the back, and any other region of skin thatwould benefit from improved hydration, elasticity, improved texture, andreduced fine lines and depressions.

The head of the device is placed into contact with a boundary of theselected area of skin to be treated. The user activates the device, forexample, by pressing trigger. While the device remains in contact withthe skin, one aliquot of composition is delivered into the area,simultaneously from each of the needles, at spaced apart injectionpoints. Thus, when using the exemplary device shown and described, fouraliquots or doses of composition are delivered simultaneously into theskin at about 10 mm apart, at a depth of about 0.5 mm to about 3.0 mm,for example, about 1 mm. While the device is still positioned againstthe skin, the user releases the trigger and the needles are retractedfrom the skin. Once the needles have retracted, the user moves thedevice laterally to an adjacent region of the skin, and the user againactivates the device, delivering another set of doses.

Interestingly, the structure of the present device allows the user tomaintain the device in contact with the skin during the treatment andbetween trigger presses. Because the needles retract into the head andbehind the distal-most region of the head (such as shown in FIGS. 2 and6) instead of lifting the device between subsequently delivered doses,the user may safely slide the device head on the skin to the nextportion of skin in the treatment region before pressing the trigger todeliver the next set of doses.

The device may be structured to reduce or mitigate pain or anxiety inthe patient. As mentioned above, the structure of the present invention,for example, when used as described, provides squeeze/slide action overthe face or other treatment region. This feature may improve the comfortof the patient's experience, for example, in that the patient is notsubjected to repeated lifting and contact of the device head on herskin, which may be relatively unpleasant to the patient and cumbersometo the physician. For example, when being treated with the presentdevice, the patient may experience the treatment as a continuous, rathersmooth, uninterrupted process, even between trigger presses, as thedevice maintains contact with the skin rather than the device needing tobe repeatedly lifted and reapplied. Furthermore, the structure of thedevice provides an additional advantage in that it enables doses to bedelivered without need to press the needles, or even the device head,into the skin. The doses are delivered by rapid trigger action asdescribed herein, while the device is in gentle contact with the skin.Advantageously, the conical portions 44 described elsewhere herein mayalso provide some pain relief to the patient, by preloading orstretching the skin immediately prior to the injection, thereby possiblyreducing or mitigating pain caused by the needle prick. In a similarrespect, it is also contemplated to be within the scope of the inventionto provide a vibrating motor on the device, effective to cause the headto vibrate when applied to the skin, thereby also mitigating pain ofinjection.

In some embodiments, the dose delivered from the sum of the needles,that is, from the plurality of needles in sum, e.g. during a singletrigger pull, is for example about 1 ml, or about 2 ml, or about 3 ml,or about 4 ml or about 5 ml. In some embodiments, the dose deliveredfrom the sum of the needles, is between about 10 μl to about 2 ml. Insome embodiments, the dose delivered from the sum of the needles isbetween about 20 μl and about 1 ml. In some embodiments, the dosedelivered from the sum of the needles is about 10 μl, about 20 μl, about30 μl, about 40 μl, about 50 μl, about 60 μl, about 70 μl, about 80 μl,about 90 μl, about 100 μl, about 120 μL about 140 μL, about 160 μL,about 180 μL, about 200 μL, about 300 μL about 400 μL, or about 500 μL,or greater.

Again, by way of example only, in some embodiments, the dose deliveredper needle of the plurality of needles, e.g. during a single triggerpull, is between about 2 μl and about 100 μl, between about 2 μL toabout 200 μl, or between about 2 and about 300 μL. In some embodiments,the dose delivered per needle per trigger pull is, for example, betweenabout 5 μL to about 100 μL, from about 10 μL to about 80 μL, or fromabout 40 μL to about 60 μL. In some embodiments, the dose delivered perneedle per trigger pull is between about 5 μl and about 50 μl, forexample, between about 10 μl and about 40 μl per needle. In someembodiments, the device is capable of providing doses from each needletip in an amount of about 6 μl, about 8 μl, about 10 μl, about 12 μl,about 14 μl, about 16 μl, about 18 μl, about 20 μl, about 22 μl, orabout 24 μl, or greater. For example, in some embodiments, the device iscapable of providing doses from each needle tip of about 30 μL, about 40μL, about 50 μL, about 60 μL, about 70 μL, about 80 μL, about 90 μL,about 100 μL, or greater. In some embodiments, the dose delivered perneedle per trigger pull is less than about 200 μL, less than about 100μL, less than about 50 μL, less than about 25 μL, less than about 10 μL,or less than about 5 μL.

In one embodiment (e.g. a four needle embodiment), the device isstructured to be capable of delivering 40 μL of composition, per triggerpull, by way of 4 spaced-apart, simultaneously injections of 10 μL. Inanother embodiment, (e.g. a ten needle embodiment), the device iscapable of delivering 100 μL of composition, per trigger pull, by way of10 spaced-apart, simultaneously injections of 10 μL. In anotherembodiment, (e.g. an eight needle embodiment), the device is capable ofdelivering 40 μL of composition, per trigger pull, by way of eightspaced-apart, simultaneously injections of 5 μL. In yet anotherembodiment (e.g. another ten needle embodiment), the device is capableof delivering 200 μL of composition, per trigger pull, by way of 10spaced-apart, simultaneously injections of 20 μL. In yet a still furtheranother embodiment (e.g. another ten needle embodiment), the device iscapable of delivering 20 μL of composition, per trigger pull, by way of10 spaced-apart, simultaneously injections of 2 μL. In still anotherembodiment (e.g. a 20 needle embodiment), the device is capable ofdelivering 400 μL of composition, per trigger pull, by way of 20spaced-apart, simultaneously injections of 20 μL. In another embodiment(e.g. a two needle embodiment), the device is capable of delivering 200μL of composition, per trigger pull, by way of 2 spaced-apart,simultaneously injections of 100 μL. These are some examples of variousembodiments of the invention, and are not intended to limit the scope ofthe invention.

In yet other embodiments, the device enables treatment of a skin surfacein a reduced amount of time, relative to conventional devices andtechniques, for example, relative to treatment of a region of the samesize using a standard needle and syringe. For example, in someembodiments, the device is capable of delivering about 1 ml to about 2ml of a fluid into skin in depots of 5 μL to about 100 μL, for example,in a time of about 45 minutes, about 30 minutes, about 20 minutes, about15 minutes, or about 10 minutes.

The device may be structured such that a desired depth of injection isachieved, for example, to achieve a target depth in the epidermis,dermis or the hypodermis. It will be appreciated that the desired depthof injection may be at least somewhat dependent on the area of skinbeing treated, and/or the desired aesthetic or therapeutic effect to beachieved.

Embodiments of the invention include needle lengths, for example,lengths of between about 2 mm to about 20 mm, for example, a needlehaving a length of about 2 mm, about 3 mm, about 4 mm, about 5 mm, about6 mm, about 7 mm, about 8 mm, about 9 mm, about 10 mm, about 11 mm,about 12 mm, about 13 mm, about 14 mm, about 15 mm, about 16 mm, about17 mm, about 18 mm, about 19 mm, or about 20 mm, or other lengthsuitable for delivering composition at a desired depth. In someembodiments, the needle gauge is 18 G, 22 G, 25 G, 27 G, or 30 G orthinner. In some embodiments, the needle gauge is at least 27 G up toabout 34 G, for example, 30 G, 32 G, 33 G, or 34 G.

By way of example, the device may be structured to achieve treatment ofskin by injection of composition at a very shallow level, for example,at a depth of about 0.1 mm or about 0.5 mm to about 2 mm or about 3 mm,into the epidermis. In other embodiments, deeper injection into the skinmay be achieved. For example, in some embodiments, the depth ofinjection is between about 2 mm to about 4 mm. Even deeper injectionsmay be between about 4 mm to about 10 mm, or even about 12 mm to about15 mm in depth. In some embodiments, the depth of injection is about 0.5mm to about 2 mm. In other embodiments, the depth of injection is about4 mm to about 10 mm. In other embodiments, the depth of injection, isabout 5 mm to about 12 mm.

Methods for using the device may include the step of moving the devicealong the skin between doses so as to effect subsequent, spaced apartdoses so as to treat a desired surface area of skin with spaced apartinjections. In some embodiments, the method includes deliveringsubsequent doses (each dose including delivery of composition from theplurality of needles) at spaced apart regions of the skin. For example,in some embodiments, the doses are spaced apart by about 5 mm and about20 mm, for example, wherein the doses are spaced apart by about 10 mm,or about 15 mm. By thus moving the device along the skin between triggerpulls, a large surface area of skin can be treated by closely spacedapart injections.

Example

For the sake of simplicity, the following example, refers to afour-needle device, for example, device 10, but it should be appreciatedthat a similar sequence of steps can be used, mutatis mutandis, withother embodiments of the invention, which include, for example,different numbers and/or arrangements of needles.

A 43-year old woman complains to her dermatologist that she isdissatisfied with the appearance of her face, and more specifically, herskin. The dermatologist observes that the woman's facial skin, whilehaving relatively few wrinkles and lines that are common to women herage, appears dry and blotchy, and the texture irregular, with highlyvisible pores and old acne scars in the form of shallow depressions.

The physician explains to the woman that a traditional dermal fillertreatment would be helpful to fill in the few, and mostly insignificant,wrinkles, but that such traditional dermal filler treatment would notnecessarily provide what she is looking for, that is, an improvement inthe overall appearance of her skin, e.g. restoration of a youthful glow,decreased dryness, and improvement in texture and smoothness. Thedermatologist recommends a microinjection treatment using a device (e.g.device 10) as described herein, to introduce, through multiple shallowinjections, a hyaluronic-based composition, which may contain vitamins,antioxidants and/or other beneficial ingredients. The patient agrees toundergo the treatment.

Beginning near the jawline of the patient, the dermatologist gentlyplaces the distal end of the device on the skin. Without pressing thedevice into the skin, e.g. any more than is necessary to simply maintaingentle contact therewith, the physician presses the trigger. Four dosesof composition are simultaneously delivered from the needles shallowlyinto the skin. Each needle delivers a single drop of the composition,for example, about 10 μl. A single trigger squeeze delivers thereforabout 40 μl of the composition (4×10 μl) into a region of skin about 40mm in length. The depth of the injection is between about 0.5 mm andabout 3 mm. The needles automatically retract. While retaining contactwith the skin, the dermatologist slides the device laterally along theface, a distance of only about 5 to about 10 mm, and again presses thetrigger. A second injection is administered, e.g. another 40 μl providedthrough the four needles. The dermatologist repeats the slide andtrigger action until the region of skin has been treated with multiple,shallow injections of small drops of the composition. After 25 triggerpulls, or in other words, 25 deliveries of 40 μl doses (4×10 μl), about1 ml of composition has been delivered to the skin (40 μl×25=1 ml).

The physician next ejects the spent cartridge from the device, andreplaces it with a new full 1.0 ml cartridge (see FIG. 16). Thedermatologist also removes and replaces original, spent head with a new,unused head 14 (see FIG. 13-15), the new head having brand new, sharpneedles (the needles of original head having become dull from the 25injections). The dermatologist repeats the treatment on the otherportion of the patient's face using the new head and a new cartridge.This process is repeated until the full skin area is treated as desired.The procedure is relatively painless and fast, and takes only about 20to about 45 minutes. The patient is told to wear sunscreen when she isoutdoors and to drink plenty of water over the next few days to protecther newly treated skin.

Within several days of treatment, the patient notices a visibleimprovement of her complexion. Her skin is noticeably suppler and lessdry, more hydrated. The minute acne scar depressions are nearly gone,and her pores appear less visible. She returns to the dermatologist fora follow up treatment every 6 weeks, and tells him she is pleased thather face has a more youthful glow.

Although the invention has been described and illustrated with a certaindegree of particularity, it is understood that the present disclosurehas been made only by way of example, and that numerous changes in thecombination and arrangement of parts can be resorted to by those skilledin the art without departing from the scope of the invention, ashereinafter claimed.

What is claimed is:
 1. A dermal filler injection device comprising: ahousing including an interior space for containing a cartridge; atrigger coupled to the housing; a head in communication with theinterior space and including plurality of dosing chambers, and aplurality of retractable needles coupled thereto; wherein the device isstructured such that operation of the trigger initially causes theneedle to be moved from a retracted position to an extended position andsubsequently causes a dose of fluid contained in the dosing chamber tobe ejected from the needle when the needle is in the extended position;the device further structured to cause retraction of the needles afterthe dosing; and a mechanism capable of filling each dosing chamberbetween subsequent injections.
 2. The device of claim 1 wherein theplurality of needles comprises adjacent needles spaced apart by about 10mm.
 3. The device of claim 1 wherein the plurality of needles comprisesadjacent needles spaced apart by less than about 10 mm.
 4. The device ofclaim 3 wherein the plurality of needles comprises adjacent needlesspaced apart by about 3 mm.
 5. The device of claim 3 wherein theplurality of needles comprises adjacent needles spaced apart by about 5mm.
 6. The device of claim 3 wherein the plurality of needles comprisesadjacent needles spaced apart by about 7 mm.
 7. The device of claim 1wherein the plurality of needles comprises adjacent needles spaced apartby more than about 10 mm.
 8. The device of claim 1 wherein the pluralityof needles comprises adjacent needles spaced apart by about 12 mm. 9.The device of claim 1 wherein the plurality of needles comprisesadjacent needles spaced apart by about 14 mm.
 10. The device of claim 1wherein the plurality of needles comprises adjacent needles spaced apartby about 3 mm to about 14 mm.
 11. The device of claim 1 wherein theplurality of needles comprises linearly arranged needles.
 12. The deviceof claim 1 wherein the plurality of needles comprises at least fourlinearly arranged needles.
 13. The device of claim 1 wherein theplurality of needles comprises a two by two array of needles.
 14. Thedevice of claim 1 wherein the head further includes a plurality ofconical or tapered projections, each needle having a tip protruding froman individual conical or tapered projection.
 15. The device of claim 14wherein each conical or tapered projection is spaced apart from eachother conical or tapered projections so as to effect a preloading ofskin when the head is applied to skin, to facilitate penetration of theneedle tips into the skin.
 16. A device for treating skin, the devicecomprising: a handpiece having a distal end; a cartridge for containingan injectable fluid; a mechanism for moving the injectable fluid towardthe distal end; and an injector assembly at said distal end, theassembly comprising multiple needles and multiple conical or taperedprojections, each needle having a tip protruding from an individualconical or tapered projection, and each conical or tapered projectionbeing spaced apart from each other conical or tapered projections so asto effect a preloading of skin when the distal end is applied to skin,to facilitate penetration of the needle tips into the skin.
 17. A methodfor treating skin comprising: placing a distal end of a handheld deviceinto direct contact with skin to be treated, the device including aplurality of needles; causing the device to deliver a dose of acomposition into a portion of the skin through the plurality of needles,substantially simultaneously; moving the distal end of the device ontoanother portion of the skin while maintaining the direct contact withthe skin; after the step of moving, causing the device to deliveranother dose of the composition into the another portion of the skin.18. The method of claim 17 wherein the needles are in a retractedposition during the moving step.
 19. The method of claim 17 wherein thedose is between about 10 μl to about 2 ml.
 20. The method of claim 19wherein the dose is between about 20 μl and about 1 ml.
 21. The methodof claim 20 wherein the dose is about 40 μl.
 22. The method of claim 17wherein the dose delivered is between about 5 μl and about 50 μl perneedle.
 23. The method of claim 17 wherein the dose delivered is about10 μl per needle.
 24. The method of claim 17 wherein the doses arespaced apart by about 5 mm and about 20 mm.
 25. The method of claim 17wherein the doses are spaced apart by about 10 mm.
 26. The method ofclaim 17 wherein the doses are spaced apart by about 15 mm.
 27. A methodof treating skin comprising using the device of claim 1 to inject acomposition into skin.
 28. A dermal filler injection device comprising:a handpiece comprising a handpiece housing including an interior spacefor containing a cartridge having a plunger slidable within thecartridge, and a trigger coupled to the housing; a head, incommunication with the interior space, the head comprising a needlearray housing assembly and a needle hub disposed within the needle arrayhousing assembly and at least one needle secured to the needle hub;wherein the device is structured such that operation of the triggerinitially causes the needle to be moved from a retracted position to anextended position; and the head being manually separable from, andreplaceable with respect to, the handpiece.
 29. The device of claim 28further comprising at least one dosing chamber in communication with theat least one needle.
 30. The device of claim 29 wherein the at least oneneedle comprises a plurality of needles and the at least one dosingchamber comprises a plurality of dosing chambers, with each needle beingin communication with a corresponding dosing chamber.
 31. The device ofclaim 29 wherein the at least one dosing chamber is disposed in thehandpiece.